How We Tested & Bandwidth

AMD has supplied us with its top-end FX-8150 processor for testing. Thankfully, the FX range is unlocked and the Asrock Fatal1ty 990FX motherboard allowed us to enable just six, four or two cores. This board also allows customization of the Turbo Core and Max Core multiplier. This allowed us to mimic the performance from the lesser three FX processors launching today: the FX-8120, FX-6100 and FX-4170.

Compared to the Phenom II, AMD's FX processors provide significantly more memory bandwidth. Read throughput has been increased by roughly 60%, while write performance is almost 40% better. Although the bandwidth performance has been improved greatly, it's still considerably slower than Intel's Sandy Bridge processors.

The L2 cache performance has also been improved -- at least when looking at the Phenom II range. The FX-8150 delivered 30% more read throughput than the Phenom II X6 1100T, though the write performance was slightly slower. As with the previous chart, Bulldozer just can't match Sandy Bridge's L2 cache performance.